Abstract 5299: Monitoring of ovarian cancer recurrence and progression via Lumipulse G CA125II assay

• Published in: Cancer research (Chicago, Ill.) Ill.), 2015-08, Vol.75 (15_Supplement), p.5299-5299
• Main Authors: Radwan, Rachel R., Raju, Savitha S., Gannon, Sara J., Le, John, Jones, Sharee D., Peacock, Catherine, Falcone, Katherine, Young, Julianna T., Li, Zhong-Qian, Dickson, Diana L.
• Format: Article
• Language: English
• ISSN: 0008-5472; 1538-7445
• DOI: 10.1158/1538-7445.AM2015-5299

CA125 is useful for monitoring the course of ovarian cancer. The correlation between CA125 serum levels and the course of the disease was reported to be 87% (Kenemans, 1993). Persistently rising CA125 levels may be associated with malignant disease and poor response to therapy, whereas decreasing CA125 assay values may indicate a favorable response to therapy (Bast, 1984; Atack, 1986; Schilthuis, 1987; Crombach, 1985). This study was to evaluate the use of LUMIPULSE G CA125II assay with patient serum or plasma for the monitoring of the recurrence and progression of ovarian cancer. METHODS: LUMIPULSE G CA125II assay is a second-generation CA125 immunoassay using monoclonal antibody (MAb) OC125 as the solid phase antibody and the MAb M11 as the labeled antibody. In the assay, serum or plasma was added to and incubated with the MAb OC125-linked magnetic particles. The particles were then washed and rinsed to remove unbound materials. Alkaline phosphatase-labeled MAb M11 was added to and incubated with the CA125-bound particles. The particles were then washed and rinsed again to remove unbound materials. Substrate 3-(2′-spiroadamantane)-4-methoxy-4-(3”-phosphoryloxy) phenyl-1, 2-dioxetane disodium salt (AMPPD) solution was then added to and mixed with the particles. Luminescence signals were thus generated by the cleavage reaction of dephosphorylated AMPPD and converted into the amount of CA125 in the serum or plasma. RESULTS: In the monitoring study, changes in CA125 levels in serial serum samples collected in SST tubes from 61 patients with ovarian cancer were compared to changes in disease status, that is, progression or no progression. A total of 297 pairs of observations were undertaken with an average number of 5.9 observations per patient. A positive change in CA125 was defined as an increase in the value that was at least 20% greater than the previous value of the assay. 67% of the 52 patient samples with a positive change correlated with the disease progression of ovarian cancer while 75% of the 245 patient serial samples with no significant change in CA125 value correlated with no progression of ovarian cancer. The total concordance was 73%. A ROC curve for the diagnosis of progression of ovarian cancer from the ratio of successive CA125 readings showed an area under the ROC curve (AUC) of 0.727 with SE 0.047; this is highly statistically significantly better than the no-association AUC of 0.5. In addition, a reference range study of this assay showe